So far, conventional writing tools such as fountain pen, pencil, ball point pen, coloring pencil and writing brush on the market are all linear in shape. That is, a writing head and a holding stick of a writing tool are substantially coaxial. Owing to the limit of people's palm structure, the writing tool generally tilts rearward the wrist while being used so that the vision line of the user will be obstructed by the writing tip of the writing tool. As such, there are several defects in writing or drawing with the conventional writing tool. First of all, a user cannot clearly see the space behind the writing tool along the vision line, so it is difficult for the user to write straight or draw in position. Especially for kids, they are likely to change their sitting posture, e.g. lie their heads upon the desks, while writing in an attempt to bypass the blockage of the vision line by the writing tool, and it is harmful to kids' eyesight and bone.
In addition, people are used to holding the writing tool slantwise, so the linear shape of the writing tool results in the slant of the writing portion relative to the working surface, and as such, the user gets no right point to exercise the pressing point and has to exert more stress on the working surface while writing or drawing. The inevitable fatigue would ruin children's interests in writing. Furthermore, the slant of the writing portion relative to the working surface makes the drawing operations with an assistant tool such as a ruler unable to achieve the best effect, since the writing tip will not be in close contact with the side surface of the ruler.
Moreover, under special writing conditions, the writing operation may suffer from the interruption of ink provided that an ink-type pen such as a ball point pen, is used. For example, if a user would like to write on a substantially vertical surface at a position higher than his head, a pen will be held slant so that the writing tip becomes higher than the ink reservoir. It is apparent that such an orientation of the pen is likely to result in the interruption of the ink owing to the adverse flow of the ink from the writing tip due to gravity. Even if the writing operation is performed on a substantially vertical surface at a relatively low position, for example lower than the height of the user's chest, the wrist of the user's writing hand has to significantly and uncomfortably bend toward the user's body in order to assure of good contact between the writing tip and the writing surface for smooth writing.
The present inventor found that the above problems can be solved by providing a nonlinear writing tool called an "offset pen" hereinafter. An offset pen includes an intermediate portion between a holding portion, i.e. the pen stick, and a writing portion, i.e. the writing head, to make the holding portion and the writing portion positioned in different axes. For example, FIGS. 1.about.3 schematically show how is an offset pen used to solve the above problems.
Please refer to FIG. 1A in which an offset pen including a holding portion A, an intermediate portion B and a writing portion C is shown. Owing to the presence of the crooked intermediate portion B, the axis of the writing portion C and that of the holding portion A will intersect at a certain angle to create a space therebetween. In addition, the angle between the writing portion C and the working surface can be made to be approximately 90 degrees owing to the offset of the writing portion. As such, the vision line of the user will not be obstructed by the writing tool as by the front portion P1 of a conventional pen. Accordingly, the writing operation of the user will proceed relatively smoothly. Furthermore, the crooked intermediate portion B provides an additional structure suitable for user's index finger to rest and exert force thereon, as shown in FIG. 1B, so as to lessen the load of user's fingers. The effect is especially prominent for duplication with carbon paper.
Please refer now to FIG. 2 in which an offset pen is used together with a ruler R. By using an offset pen including a holding portion A, an intermediate portion B and a writing portion C as mentioned above, the writing portion C is approximately perpendicular to the working surface K so as to be in close contact with the side surface R2 of the ruler R. As such, the user will be able to draw a line precisely as desired without being influenced by his palm structure and the thickness of the ruler.
FIGS. 3A and 3B schematically show the situations of the offset pen for use to write on a vertical surface at a relatively high and a relatively low positions, respectively. Referring to FIG. 3A, the crooked intermediate portion B allows a section of the ink reservoir B1 to remain higher than the writing tip C1 so as to avoid the interruption of the ink. Referring to FIG. 3B, the pen-holding posture can be adjusted to be comfortable by simply turning the offset pen by 180 degrees using the holding portion of the pen as the turning axis.
Even though advantageous over conventional linear pens in many aspects, the offset pen encounters problems in manufacturing and assembling. It is complicated to produce a crooked and hollow pen structure. Furthermore, the ink refill or reservoir is difficult to be installed into the crooked pen structure, and also inconvenient to be replaced.